While this Blumhouse production may be a less ruthlessly efficient scream machine than, say, its corporate sibling "Ouija," it is much more atmospheric and benefits from a winning central performance from Snook.

If the result features around 1,783 too many fart gags, to be fair, it also boasts a couple of genuine minor scares. Although there's no doubt that the film's most horrible sight is a way-too-long shot of Swardson's naked rump.

The first, pre-'quake half hour is such a patience-testing slow burn that director Nicolás López runs the risk of extinguishing the viewer's interest altogether. But when things head (metaphorically) south they do so with an escalating, apocalyptic ferocity which continues until the very last second.

While this religio-horror effort does contain some nice scares, and a memorably unnerving turn from Crowley, The Devil Inside's biggest shock arrives when it abruptly ends - just as it hits its stride. The result is a found-footage movie whose third act remains missing.

Consider this a public service announcement: Folks who have a problem with onscreen flesh-hacking - or the fact that franchise stars Jean-Claude Van Damme and Dolph Lundgren aren't in the movie all that much - should stay home.

To be fair, Eckhart is physically impressive and Bill Nighy and his raised eyebrow do their best in the role of demon leader Naberius. But I, Frankenstein shares something else with it's monster-hero, something much worse than its patchwork nature: The film is distinctly lacking in the soul department.